Evaporation ponds explored to nourish tough forage crop

A unique way to reduce space-stealing evaporation ponds in California — and nurture a new crop in the process — has been developed by Agricultural Research Service scientists and cooperators.

In the agricultural valleys of Central California, some evaporation ponds aren't worth keeping. Farmers who tend the region's heavily irrigated lands use these ponds to catch excess runoff draining from saturated fields.

On the west side of California's San Joaquin Valley, for every nine acres of land in production, one acre is needed for an evaporation pond, according to ARS soil scientist Dennis Corwin. For many growers in the valley trying to raise cotton, wheat and alfalfa, this can represent hundreds, if not thousands, of lost acres.

Not only that, but these vast ponds have also been found to contain concentrated salts and trace elements, including selenium, boron and arsenic, that can be toxic to wildlife and migratory birds seeking a watering hole in California's desert.

Corwin, who works at ARS' George E. Brown, Jr., Salinity Laboratory in Riverside, Calif., and researchers at the University of California (UC) at Davis and UC-Riverside experimented to see if water pumped from an evaporation pond could actually be used to help nourish a tough and hardy forage crop.

If so, the pond's waters might start drying up, benefiting growers and wildlife and helping make less-arable land profitable again.

The team of soil, plant and animal experts is in the sixth year of their project. According to Corwin, the test crop — a salt-loving Bermuda grass — appeared to languish at first, given its less-than-favorable environment. But now it is lush and supporting a herd of beef cattle.

According to Corwin, the project exemplifies how even poor water and soil conditions can be overcome with the right combination of scientific knowledge and farmer expertise.